Recently, various communication services have been provided through networks such as the Internet. Of the various communication services, real time supply is highly important for services that provide media such as audio materials and movies, and discontinuation of communication, communication delay, and other communication troubles are more likely to directly lead to a deterioration in the quality of the services.
To address this issue, there are various techniques proposed for managing quality of service (QoS) of the mobile communication network and the fixed communication network, as described in Patent Documents below.